Abstract:
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With the advent of flexgrid optical networks, the rigid wavelength-division multiplexing (WDM) technology
will be enhanced by providing better spectrum efficiency and flexibility. In those future flexible optical
networks, optical connections (lightpaths) can allocate a flexible number of spectrum slices, also known as
frequency slots, so to match better with its requested bitrate. In this paper, we propose to take advantage of this
flexible spectrum allocation in recovery mechanisms to be triggered when a failure occurs to provide recovery of
part of the requested bitrate, i.e. the allocated spectrum by backup lightpaths could be lower than that of the
working lightpaths provided that client service level agreements are fulfilled. This reduction in the recovered
bitrate (bitrate squeezing) allows optimizing the use of network capacity. We propose path-based recovery
alternatives, based on protection and restoration, specially designed for flexgrid networks. The performance of
the proposed recovery mechanisms is exhaustively evaluated on a national reference network |